On the tragic evening of November 13, 1974, a young man shoots and kills his entire family with a 35-caliber Marlin rifle as his parents, two brothers and two sisters apparently sleep. The gruesome murder of the DeFeo family shakes up the sleepy Long Island town of Amityville—and leads to decades of horror storytelling. Ronald “Butch” DeFeo Jr. told people that night at an Amityville bar that his parents had been shot inside his home, an upscale dwelling with a statue of the Virgin Mary and a sign declaring "High Hopes" in front. Several bar patrons accompanied him back to...